#include<iostream>
using namespace std;
int n,x[20],s=0,i,sum=0;
void dfs(int a,int b,int c,int m){
	if(s>0)return;
	if(a>sum||b>sum||c>sum)return;
	if(m==n){
		if(a==b&&b==c)s++;
		return;
	}
	dfs(a+x[m],b,c,m+1);
	dfs(a,b+x[m],c,m+1);
	dfs(a,b,c+x[m],m+1);
}
int main(){
	cin>>n;
	for(i=0;i<n;++i){
		cin>>x[i];
		sum+=x[i];
	}
	if(sum%3)cout<<"no";
	else{
		sum/=3;
		dfs(0,0,0,0);
		if(s)cout<<"yes";
		else cout<<"no"; 
	}
	return 0;
}